Data Manipulation (SQL/Python) Interview Questions
Practice 656 real Data Manipulation (SQL/Python) interview questions for 2026. Covers companies like Meta, Amazon, TikTok, DoorDash, and Capital One. Real questions from actual interviews with detailed solutions — designed for focused interview preparation for data analysts, data scientists, and data engineers who must move fluidly between SQL and Python during live screens and take-home tasks. These questions emphasize practical skills: writing correct, efficient SQL (joins, GROUP BY, window functions, CTEs, NULL handling, and performance-aware predicates) and idiomatic Python/Pandas solutions (vectorized transforms, merges, reshaping, datetime handling, and robust data-cleaning). Interviewers evaluate correctness, edge-case reasoning, runtime and memory tradeoffs, reproducibility, and clear communication of assumptions. Expect timed whiteboard-style queries, pair-programming in a shared editor, and take-home notebooks. To prepare, practice translating SQL ↔ Pandas, explain results aloud, time-box exercises, test edge cases, and review common pitfalls such as NULL semantics, grouping logic, off-by-one errors, and inefficient joins.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Count unconnected posts and reactions
You are analyzing a newly launched feed feature intended to improve engagement by showing more unconnected content. Assume the following tables: - pos...
Write SQL for reply-based recipient metrics
You work on a social product and are given two tables. Assumptions (use these unless you state otherwise): - All timestamps are in UTC. - A “reply” is...
Write SQL for repeat churn
Write a SQL query to measure the performance of a free-month promotion experiment. Assume experiment_users already contains only users who were eligib...
Query departments and top earners
You are given three tables: 1. company - employee_id INT - first_name VARCHAR - last_name VARCHAR - department VARCHAR - salary DECIMAL...
Calculate Cohort Retention
You are given two tables: users - user_id BIGINT PRIMARY KEY - signup_ts TIMESTAMP user_events - user_id BIGINT - event_ts TIMESTAMP - event_name VARC...
Compute churn with re-subscriptions
You are analyzing a free-month subscription experiment. Assume experiment eligibility has already been computed; every user in the experiment table is...
Write SQL for call metrics
You have two tables. calls ( call_id BIGINT, sender_id BIGINT, receiver_id BIGINT, call_ts TIMESTAMP, picked_up BOOLEAN, call_type VARCHAR...
Find high-value crypto users and top CTR
You are given three tables. Assume all timestamps are stored in UTC. - users(user_id BIGINT PRIMARY KEY, create_date TIMESTAMP): one row per user acco...
Write SQL for top categories and highly active users
You are given three tables: 1) impression Event-level table of user impressions. - impression_id BIGINT (PK) - user_id BIGINT (FK → user.user_id) - pi...
Compute Cohort Retention Rate
You are given two tables: - users(user_id BIGINT, signup_ts TIMESTAMP) — one row per user. - user_activity(user_id BIGINT, activity_ts TIMESTAMP, even...
Explain Pandas and SQL Basics
You are interviewing for a Data Engineer internship. Answer the following short data-manipulation questions: 1. In pandas, what is the difference betw...
Analyze advertiser spend by source
You are given two tables: advertisers - advertiser_id BIGINT - advertiser_type VARCHAR — examples: smb, enterprise, agency, internal - status VARCHAR ...
Handle repeated churn in SQL
As part of analyzing the same promotion experiment, you need SQL that handles users who churn and later resubscribe. Assume the following tables: 1. e...
Calculate Pirated Usage and Revenue Loss
You are analyzing theme piracy on an e-commerce platform. Assume the analysis window is 2023-01-01 through 2023-12-31, all timestamps are stored in UT...
Write SQL for DAU and first-purchase conversion
Today is 2025-09-01. Using the schema and sample data below, write a single ANSI-SQL query that returns one row per day for the last 7 days (2025-08-2...
Write SQL for multi-account metrics
A consumer app allows one user to own multiple accounts. Use SQL to answer the following questions. Assume the database has these tables: accounts - a...
Differentiate pandas objects and SQL filters
Python (pandas) 1. What is the difference between a pandas Series and a pandas DataFrame? - Discuss structure (1D vs 2D), indexing, column labels, ...
Find high-value crypto users and top-CTR product
You are given three tables (timezone: UTC). Assume create_date, transaction_time, and event_time are timestamps. Tables users - user_id BIGINT PRIMARY...
Debug row loss after SQL joins
You are reviewing a buggy SQL query used by a retail analytics team at a home-improvement company. The query is supposed to return daily promo sales f...
Analyze video flags and reviews with SQL
You are designing SQL queries for YouTube Trust & Safety. Use the schema and sample data below. Unless stated otherwise, treat a flag as reviewed if t...